Tetranuclear Dysprosium(III) Quintuple-Decker Single-Molecule Magnet Prepared Using a π-Extended Phthalocyaninato Ligand with Two Coordination Sites.

The magnetic properties and spin relaxation processes of a tetranuclear dysprosium(III) fused phthalocyaninato (Pc4- ) quintuple-decker single-molecule magnet (SMM) (1) with non-equivalent octa-coordination geometries are reported. The structure of 1 is regarded as a dimer of Dy3+ -Pc triple-decker SMMs with different magnetic relaxation characteristics, corresponding to the octa-coordination geometry sites Dy1 with C4 symmetry (ϕ1 =23°) and Dy2 with D4d symmetry (ϕ2 =45°). In an Hdc of 1750 Oe and T range of 1.8-3.75 K, the quantum tunnelling of the magnetization was suppressed, and the direct process was enhanced. The effects of the coordination geometry on the spin relaxation phenomena are examined.